All human surfaces harbor bacteria; some have favorite places. Certain forms of non-pathogenic streptococci limit their homesites to the first millimeter of oral mucosa at the gumline. Common forms of staphylococcus are found in a third of asymptomatic noses. By virtue of their role in touching public items, procuring food, picking noses, satisfying itches and handling-the-paper chores, the thumb and first two fingers probably provide the greatest sample and volume of bacteria from the daily environment. If those digits carry pathogenic E. coli, Salmonella or methicillin-resistant Staph aureus (MRSA), you may have a major health problem. If they invite more ordinary bacteria and viruses to the kitchen and dinner table, you may just get sick for a few days.
One way to stay healthy is to reduce the bacterial count on the hands. It is impossible, even with a ten-minute surgical scrub, to eliminate all of them. A unique problem exists in the nail beds, where accumulated oil and dirt may provide a refuge for bacteria and be hard to displace. Soaps and detergents act in two ways. Their main role is to cut the grease and soften the buildup under the nails and in the cuticles. They may also directly injure the cell membranes of bacteria, affecting their mobility or even killing them. Soaps and detergents require sufficient time and concentration at the work site to be effective.
Commonly used bactericidal chemicals intended for use on skin, for example, antiseptics, include iodine and mercury compounds, phenol, alcohol, benzalkonium chloride, mineral spirits, propylene glycol, chlorhexidine and hexachlorophine. Their role in routine hand cleaning is limited by their potential to irritate skin.
A number of devices have been developed over the years for assisting in the cleaning of fingertips, particularly the hard-to-clean nail beds and cuticles. However, each of these devices has at least one drawback, ranging from low cleaning efficiency to difficulty in cleaning the device between uses, among others.